Transfer Unit; Cleaning Unit - Lexmark C920 Service Manual

As the photodeveloper rotates, it comes into contact with toner on the development roll of the cartridge. Due to
the charge differences between the electrostatic image and the rest of the surface of the photodeveloper, toner
will only cling to the electrostatic image created by the light from the LED printhead.

Transfer unit

Paper is fed onto the transfer belt by the registration rollers while the belt rotates at the same speed as the
photodevelopers. The paper is held to the belt by an electrostatic charge from a charge roller located inside the
belt.
As the paper reaches each color position, a transfer sheet located inside the belt (underneath the paper) will
apply a charge to the paper. The charge difference of this electrostatic field will cause the toner image formed on
the photoconductor drum to transfer to the paper.

Cleaning unit

Any toner that remains on the photodeveloper following transfer is scraped away with the cleaning blade and
collected in the waste toner reservoir. Furthermore, the residual charge that remains on the photodeveloper is
discharged by the erase lamp. Once this process is complete, the photodeveloper is ready to begin the EP
process for the next page.
5056-XXX
3-25
Diagnostic aids